Choo-Choo Charles

Charles, whenever he shows up while the player is in the locomotive. Charles will pursue the player along the tracks while tearing at the engine, while the player shoots back at him with one of their train-mounted turret weapons. If Charles doesn’t cause enough damage to the train to drag the player out and eat them, the monster will retreat into the forest to recover after enough of his health is shaved off.

Example of:
Advancing Boss of Doom